Permeation and immersion testing will be performed on four types of commercial polymeric chemical protective clothing (CPC) materials challenged with several organic solvents from each of 14 chemical classes. Binary mixtures will be examined for a representative subset of these solvents. Experimental results will be used to develop and validate predictive models of the equilibrium solubilities, diffusion coefficients and permeation rates of the solvents for each type of CPC material. Key issues to be addressed are the influences of solvent structure, CPC-polymer structure and crosslinking, temperature, and the nature and concentration of co- solvents. Solubility prediction models will be based on 1) three- dimensional solubility parameters and 2) solvatochromic indices in conjunction with linear solvation free-energy relationships. Models for predicting diffusion coefficients will be based on empirical correlations of measured values with the physical properties and CPC-interaction strengths of the solvents. Solubility and diffusion coefficient values will be used in Fickian models to obtain quantitative predictions of solvent breakthrough times and steady-state permeation rates.